This invention relates to metal cords for use as reinforcement, particularly for reinforcing deformable articles made of elastomeric material such as pneumatic tires, conveyor belts and high pressure hoses, but also usable to reinforce substantially rigid synthetic materials such as polyesters.
When used to reinforce deformable articles such as those just mentioned, such metal cords are subjected to tension stresses, bending, axial compression, internal abrasion, corrosion, fatigue, and other stresses.
An example of a metal cord for such a purpose is shown in British Pat. No. 1,034,327.
In some applications, an improved rubber penetration is desirable in order to avoid adhesion breakdown with consequent corrosion propagation along individual reinforcing cords, resulting in premature destruction of the reinforced body. This type of reinforcement also ensures better adherence of the reinforcing cords to the matrix when used in rigid materials. This difficulty has been avoided in small cords by a 2+ 7 construction. Cords consisting of three filament layers, in use at present, still suffer from this problem, particularly in the range of intermediate strength cords consisting of from 15 to 27 filaments.